One of the decisions each campus has to make, early in the process of doing a greenhouse gas inventory, is where to set the borders, or boundaries, to be analyzed. What geographic locations will be included? What vehicles? What activities? Defining scope is probably the most important task, at the outset.
The fundamental international set of guidelines on how to do this stuff, the Greenhouse Gas Protocol, establishes three basic scopes for studying emissions. Scope 1 includes GHG that is created directly from the activities your organization performs. For instance, if I drive a Greenback-owned truck across campus as part of my job, the emissions created fall into Scope 1.
Scope 2 includes emissions which the organization doesn't create directly, but rather hires out to utilities or other similar suppliers. The GHGs created in generating the electricity we use on campus, or the steam we purchase to heat our buildings -- those are Scope 2 emissions.
Scope 3 includes everything else. When I commute to campus, the emissions are Scope 1 to me as an individual, but they're Scope 3 to Greenback (after all, if Greenback didn't require me to work on campus, I wouldn't be commuting.) When I travel by air on business, the emissions created are Scope 1 to the airline company, but Scope 3 to Greenback (because it was Greenback's decision to send me on that trip). When I use a ream of paper in the printer, ... well, you get the idea.
Now, all the various organizations that are encouraging campuses, and companies, and communities to inventory their greenhouse gas emissions (and then figure out how to reduce them) delineate various combinations of Scope 1, 2 and 3 emissions for inclusion. The Presidents Climate Commitment requires inclusion of all of Scope 1, all of Scope 2, and some specific Scope 3 emissions (commuting and institution-paid air travel). The Climate Registry (a fast-growing organization which focuses broadly, not just on IHEs), requires only Scopes 1 and 2, on the theory that all Scope 3 emissions are being counted by somebody else, for whom they're Scope 1.
Well, if your intent is to create a comprehensive set of GHG inventories across all the organizations and individuals in a society, then not counting Scope 3 makes a lot of sense. But colleges and universities aren't typical organizations, and the PCC isn't about being peers with everybody else in society, it's about providing leadership.
One simple example can bring this all down to earth. Consider the case of two otherwise identical colleges, but one of them requires all students to live on campus and the other provides no on-campus housing at all.
For the school with the housing requirement, all the emissions resulting from operating all the residence halls will be included either in Scope 1 or Scope 2 (depending on how the heating system is designed). Total campus emissions will go up. Emissions per student will go up. Emissions per square foot will probably to up (after all, the residence halls have to operate seven days a week, unlike many campus buildings).
For the school which provides no housing, these emissions can go away. The corresponding emissions (operation of the apartment buildings or other housing where the students live) don't accrue to the school, they accrue to the various landlords. And the emissions created by student commuting (which don't exist in the on-campus scenario) are Scope 1 to the students, not the school.
An old rule of management is "be careful what you measure, because that's what's going to improve". If we only measure Scope 1 and Scope 2 emissions, we're creating a perverse incentive for universities and colleges to reduce their on-campus housing. Getting students to move off campus reduces the school's emissions numbers. But having students live off campus actually increases the total greenhouse gases emitted. (Not only do off-campus students have to commute, but the housing they live in is often less energy-efficient than a residence hall.)
IHEs are unusual in that we not only conduct our business, we also decide (to some extent) where our customers live. The PCC's requirement that commuting emissions be included goes some distance toward removing the perverse incentive to have students live off campus. Finding a way to, similarly, include emissions created by the living quarters of full-time commuter students would be even better (although logistically unworkable, sigh ...).
Which gets us back to that leadership thing. If higher ed, as an industry, is going to take a leadership position in achieving sustainability, it's not enough just to do what we recommend that every other organization do. We need to go a step farther -- do a bit more. The current PCC requirements for inclusion of certain Scope 3 emissions are a small example of that. Personally, I'd like to see them expanded. (Remember that ream of paper?)